Al<sub>0.65</sub>Ga<sub>0.35</sub>N/Al<sub>0.4</sub>Ga<sub>0.6</sub>N Micro-Channel Heterojunction Field Effect Transistors With Current Density Over 900 mA/mm
Hao Xue, Kamal Hussain, Towhidur Razzak, Mikhail Gaevski, Shahadat H. Sohel, Shahab Mollah, Vishank Talesara, Asif Khan, Siddharth Rajan, Wu Lu
Abstract
We report on the demonstration of high current density in Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.65</sub> Ga <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.35</sub> N/Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.4</sub> Ga <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.6</sub> N heterojunction field effect transistors with micro-channels enabled by enhanced contact injection. Devices with a gate length of 100 nm exhibited a maximum current density of 910 mA/mm and a maximum transconductance of 140 mS/mm. A current gain cut off frequency of 20 GHz and maximum oscillation frequency of 36 GHz were obtained. Large-signal load-pull characterization of the transistors showed output power density of 2.7 W/mm at 10 GHz. The current density and output power density represent the state-of-art performance for high Al-composition AlGaN channel transistors.